Alfven Instrument to Assess Aurora’s Aura

Photonics.comFeb 2012
POKER FLAT RESEARCH RANGE, Alaska, Feb. 22, 2012 — A small rocket was launched into the aurora borealis in an attempt to discover how its physical properties affect the satellite signals received on Earth.

The two-stage, 46-foot Terrier-Black Brant rocket blasted off from the Poker Flat Research Range in Alaska, reaching a height of about 217 miles. The experiment is part of a NASA-funded study into how the northern lights affect space weather and signals on global positioning system (GPS) satellites and other spacecraft.

A two-stage Terrier-Black Brant rocket arced through aurora 200 miles above Earth as the Magnetosphere-Ionosphere Coupling in the Alfvén resonator (MICA) mission investigated the underlying physics of the northern lights. Stage one of the rocket has just separated and is seen falling back to Earth. (Image: Terry E. Zaperach, NASA)
“We’re investigating what’s called space weather,” said Steven Powell of Cornell University, the study’s lead investigator. “Space weather is caused by the charged particles that come from the sun and interact with the Earth’s magnetic field. We don’t directly feel those effects as humans, but our electronic systems do.”

The project — the Magnetosphere-Ionosphere Coupling in the Alfven resonator (MICA) mission — involves 60 scientists, engineers, technicians and graduate students from Cornell University, Dartmouth College, the University of New Hampshire, the Southwest Research Institute, the University of Alaska Fairbanks, the University of Oslo and NASA.

A fish-eye photo taken by an automated camera near the entrance gate to the Poker Flat Research Range in Fairbanks, Alaska. (Image: Donald Hampton)
Instruments on board sampled electrons in the upper atmosphere that are affected by a form of electromagnetic energy called Alfven waves. These waves are thought to be a key driver of “discrete” aurora — the typical, well-defined band of shimmering lights that is about six miles thick and stretches across the horizon.

The rocket payload separated into two parts once launched. One part extended antennae to measure electric fields generated by the aurora. Other antennae and sensors measured electrons and ions interacting with the Earth’s magnetic field. In this period of high sun activity, called solar maximum, gases from the sun are likely interfering with GPS transmissions, satellite Internet and other signals.

“We are becoming more dependent on these signals,” Powell said. “This will help us better understand how satellite signals get degraded by space weather and how we can mitigate those effects in new and improved GPS receivers.”